In 1990 two men wearing police uniforms took over the Isabella Stewart Gardner Museum in Boston. They stole works by Degas, Rembrandt, Vermeer, and Manet and got away with the biggest art heist in history. In 1997 Christopher Wallace, the influential rapper known as Notorious B.I.G., was gunned down in Los Angeles. His killer remains free. And these cases are just two among many.

When a major crime is committed, investigators search for recent "hot" clues to track down the culprit. But what happens when the trail turns cold? Many unsolved criminal cases are closed and left dormant for years. On top of that, recent DNA advances and new forensic technologies are overturning guilty verdicts and creating more unsolved cases. Unsolved Crimes presents the victims, the details of the investigation, and the suspects in each case, and "Lingering Doubts" sidebars ask unanswered questions and let you assess the situation.

Included are sections such as:

Murder: High-school student Natalee Holloway; California's Zodiac Killer; the Black Dahlia; Hogan's Heroes star Bob Crane
Political Assassinations: Communist defector Alexander Litvinenko; investigative Russian journalist Anna Politkovskava; Swedish Prime Minister Olof Palme; Pakistani leader Benazir Bhutto
Kidnapping: British child Madeleine McCann; Minneapolis socialite Virginia Piper: Moroccan leader Mehdi Ben Barka
Robbery: Airplane hijacker D. B. Cooper: the heist of the Irish "Crown Jewels"
White Collar Crime: Tainted Chinese toothpaste; the Vatican Bank Scandal